It is known that organic and polymeric materials with large delocalized .pi.-electron systems can exhibit nonlinear optical response, which in many cases is a much larger response than by inorganic substrates.
Thin films of organic or polymeric materials with large second order nonlinearities in combination with silicon-based electronic circuitry have potential as systems for laser modulation and deflection, information control in optical circuitry, and the like.
Polymers with a comb structure of pendant side chains are a new class of organic materials which exhibit interesting optical properties. In U.S. Pat. Nos. 4,694,066; 4,755,574; and 4,762,912 polymers are described which have pendant side chains which exhibit nonlinear optical susceptibility, in addition to mesogenic properties. U.S. 4,792,208 discloses nonlinear optically responsive organic compounds and side chain polymers in which the molecular dipoles have an electron donor moiety linked through a conjugated .pi. bonding system to an electron acceptor sulfonyl moiety.
There is continuing interest in the theory and practice of optically responsive polymers which are characterized by an oriented state of comb-like side chain structures.
There is also an increasing research effort to develop new nonlinear optical organic systems for prospective novel phenomena and devices adapted for laser frequency conversion, information control in optical circuitry, light valves and optical switches.
Accordingly, it is an object of this invention to provide polyvinyl copolymers having pendant side chains which exhibit a high level of nonlinear optical response.
It is another object of this invention to provide poly(maleic anhydride) copolymers and crosslinked copolymers which exhibit nonlinear optical response, and which can form optically transparent films that resist cracking and exhibit excellent adhesive properties in multilayer laminated structures.
It is a further object of this invention to provide optical waveguide media comprising a thin film of a polymer with nonlinear optically responsive pendant side chains which can be uniaxially aligned by an external field.
Other objects and advantages of the present invention shall become apparent from the accompanying description and examples.